By some estimates, 80% of new oil and gas wells are horizontal wells. Horizontal wells are deviated wellbores, which include a horizontal section. Each of these must be accurately and efficiently geosteered because time is of the essence when drilling expensive deviated wellbores and a mistake in the geosteering (drilling) can be very costly if not potentially hazardous. Most geosteering applications are stand-alone 2D applications that are not integrated with a project database and 3D geo-model. In other words, they cannot take advantage of what a full 3D environment affords and it is difficult to incorporate the 2D interpretation back into the project database and geo-model. Most 2D geosteering applications must export the horizontal well correlation data in order to then import that data back into the project database, which is a time-consuming process. Additionally, conventional 2D geosteering applications cannot display a depth converted seismic backdrop that can be dynamically updated with new or additional seismic data. In fact, many conventional 2D geosteering applications cannot support multiple type logs (e.g. signature logs) that are used for correlating the horizontal section of the wellbore into variable geology. This deficiency can lead to inaccurate correlation and incorrect geosteering instructions.
TerraVu™ is one example of a 2D geosteering application, which is marketed by Terra Domain Consulting, that is limited to a single type log for correlation purposes. Moreover, TerraVu™ is a stand-alone 2D geosteering application that does not offer a dynamic depth converted seismic backdrop and must export its horizontal well correlation data in order to read that data into the project database.
Other geosteering applications like smartSECTION™ and BoreSight™ contain different limitations. For example, smartSECTION™, which is marketed by Landmark Graphics Corporation, has limited horizontal well correlation and geosteering capability and does not support 2D model building including apparent dip angle and fault offset manipulation along the wellbore.
There is therefore, a need for a more efficient and accurate means to guide the end of a horizontal section of the wellbore to the target formation using 2D and/or 3D modeled surfaces.